Pneumatic hammer.



R. A. NORLING.

PNEUMATIC HAMMER. v APPLICATION FILED DBO. 17, 1910.

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R. A. NORLING.

PNEUMATIC HAMMER. APPLICATION FILED DEO.17 1910.

998,919. I 4 PatentedJuly25, 1911.

4 SHEETS-SHEET 4.

(2 GL2 (6 5 I UMTED STATES PAT FFIC.

REINI-IOLI) A. NORLING, OF AURORA, ILLINOIS, ASSIGNOB TO AURORAAUTOMATIC MACHINERY COMPANY, OF AURORA, ILLINOIS, A CORPORATION OFILLINOIS.

PNEUMATIC HAMMER.

Specification of Letters Patent.

Application filed December 17, 1910.

Patented July 25, 1911.

Serial No. 597,865.

' I the. accompanying drawings, and to the letters of reference markedthereomwhich form a part of this specification.

T his invention relates to a portable pneumatic tool or hammer of thatclass embracing a barrel or cylinder, a piston or plun geiadapted tomove therein, and a controlling valve through which the air or otherfluid under pressure is admitted to and aermitted to escape from theopposite ends of the cylinder or barrel to give reciprocatory movementto the therein.

The invention is illustrated and described herein as applied to achipping hammer, otherwise known as a short stroke hammer, a d consistsof the combination of parts lereinafter described and more particularlypointed out in the appended claims.

In the drawings t Figure 1 is a longitudinal section through the hammerin a. plane containing the central axis of the barrel or cylinder andthe central axis of the throttle valve chamber. Fig. 2 is a longitudinalsection through the barrel on an enlarged scale in a plane through thecentral axis thereof at an angle to the plane of Fig. 1. Fig. 3 is asimilar section through the barrel in the same plane, showing the pistonand movable valve member in dif- 'ent positions to those shown in Fig.2. -'l is a longitudinal section through the central axis of the barrelin a plane at a second angle to the plane of the section of Fig. l. (tand 7 are longitudinal sections through the. barrel taken respectivelyon the lines 5- 5. G-6, and 7-7 of Fig. 8. Fig. is a rear end elevationof the body of the barrel. 9 is a cross-section of the nner on the line99 of Fig. 1, with the mov .le valve member in the position indicated inFig. l where the plane of the section is indicated by 9 -9 Fig 10 is aside elev he valve block body. Fig. 11 a trans so section through thesame on the line 11--11 of Fig. 10. Fig. 12 is a plunger transversesection through the valve block body on the line 1212 of Fig. 11. Fig.13 is a longitudinal section through the valve block body on the line1313 of Fig. 12. Fig. 1 1 is a longitudinal section through the valveblock body on the line 14e-14 of Fig. Fig. 15 is a side elevation of thevalve block cap. Fig. 16 is a rear end elevation of the same. Fig, 17 isa longitudinal section through the central axis of the valve block capon the line 17-17 of Fig. 16. Fig. 18 is a longitudinal section throughthe valve block cap through the central axis of the same on the line1818 of Fig. 16.

In that embodiment of my invention illustrated in the accompanyingdrawings, A represents the barrel or cylinder of the hammer; B, thepiston or plunger adapted to reciprocate therein; C, the tool carryingnozzle; and D, the tool, in this case a chisel. The rear end of thebarrel or cylinder is screw-threaded as at a, to receive the forward,internally threaded end of a. hollow head E. Said hollow head E isclosed atits rear end by an end wall E and has formed integrally with ita handle F. The head E is split at its forward end and provided with alongitudinal recess 6 inclosed by apertured lugs 0 e which are drawntogether by a bolt 6 so as to rigidly clamp the thread of the head inengagement with the thread of the barrel.

G indicates a transverse passage in the tool head containing a valvebushing g. G is a throttle valve piston reciprocablymounted in saidbushing, and adapted to be operated by a stem G which projects throughan aperture G into a slot G in the handle containing a pivotally mountedlever G which operatively engages the upper end of said stem. Said leverG is actuated by a hand lover or trigger F pivotally mounted in the slotG in position to be engaged by the palm of the hand when the tool handleis grasped and connected to said lever G by a link f. An annular chamberis formed about the bushing g and is connected with the interior thereofby supply ports 9 g is an air passage leading to the annular chamberSaid passage is enlarged at its outer end and threaded to receive theusual air supply pipe (not shown).

The outer end of the transverse passage G is closed by a threaded cap 6and the opposing parts of said cap and of the piston valve G areprovided with recesses to receive the ends of a coiled spring g whichnormally holds the piston in position to close the sup ply ports 9 Thevalve mechanism for controlling the admission and exhaust of air intoand from the cylinder embraces a valve block 11* provided with exhaustand admission ports and an annular or cylindric valve ring J surroundingsaid valve block and arranged to slide endwise thereon to open and closesaid ports; said valve ring being provided with oppositely facingdifferential pressure areas. Said valve block is located at the rear endof the barrel and is made in two parts,-a body member H and a cap memberI.

The valve block body ll rests at its forward end within an annularrecess a formed in the rear end of the piston barrel A. It is providedwith a recess or chamber 72,1 in its forward face, the outer part ofwhich, if, is of slightly larger diameter than that of the barrel A,while the inner part, if, is of smaller diameter, an annular shoulder Irbeing thus formed. A dowel pin h see Fig. 4:) holds said valve blockbody against rotative movement relative to the piston barrel. The capmember I is provided at its forward end with an annular projection orstem I of nearly the length of the valve block body, which engageswithin a longitudinal, central bore in said valve bloclt body, theforward end of said stem forming; part of the rear wall. of the chamberii in the forward face thereof. The rear end of the valve block caprests against the end wall E of the plunger barrel head. The valve blockIV is thus rigidly held in place between the rear end of the cylinder A.and the end wall of the hollow head E. A dowel pin 1' (see Fig. 1) holdsthe cap I against rotative movement relative to the valve block body H,

The valve member J is in the form of a cylindric sleeve surrounding thevalve block H and is arranged. to have endwise sliding movement thereon.The valve block H is enlarged in diameter atits forward end to form anannular flange H. The valve ring J is enlarged at its forward end toembrace said flange H and is provided with an annular shoulder J on itsinner surface which is opposed to the rear face of the annular flange Hand which forms the larger pressure area of the valve ring. The valveblock cap I is made of larger diameter than the rear end of the valveblock body H so as to form a forwardly facing, annular shoulder Iextending around the rear end of the body, and the valve ring; J isenlarged. at its rear end, as indicated at J*, to'embrace said valveblock cap.

J indicates an annular rearwardly facing shoulder on the inner surfaceof the valve ring J opposite the forwardly facing annular shoulder I ofthe valve block. Said shoulder J 5 constitutes the smaller pressure areaof the valve ring J. lVithin the inner, rear, enlarged end of the valvering formed an annular groove or channel J which communicates with thespace between the shoulder J of the valve ring and the shoulder T of thevalve block in all positions of the valve ring, as shown in Figs. 1 to4-, inclusive. The forward movement of the valve ring J is limited bythe rear end of the cylinder A, while its rear movement is limited bythe end wall E of the hollow head E. The length of the valve ring J isso proportioned to the distance between the end wall E and the rear endof the cylinder A that the shoulders J and J 5 of the valve ring do notstrike the shoulders of the valve block to which they are opposed whenthe valve ring moves to its limits, but leaves a small. space betweenthem (see Figs. and 3) so that air may be readily admitted to thepressure. area of the valve ring.

K indicates a series of radial exhaust ports which are located at theforward end of the valve block body and which extend through thecylindric walls of the chamber, located in the forward end thereof. Saidports K constitute the main exhaust ports for the inner end of thecylinder and are adapted to permit the exhaust of the air from the innerend of the barrel, when the piston B is making; its rearward or returnstroke, the valve ring: J being then in such position that the ports K.are uncovered. and open to the space X about the valve, which space isfreely open to the outer air through the passage X (see Fig. 1) whichopens through the cylindric wall of the head i indicates a passageeXtx-mdine' longitudinally through the walls of the main barrel or(ylinder and which opens into the interior of the barrel at its forwardend through a port on (see Figs. 2, 6 and 9). and which is adapted. forthe exhaust of air from the outer or forward end of the cylinder duringthe outward stroke of the piston. Said pa extends through the walls ofthe valve block body H and through the valve block can, being closed atits rear end against the end wall E of the head E. The part of saidpassage M extending through the valve block is bent inwardly intermediato the ends of the valve block so as to make it possible to provide apassage of large diameter without unduly enlarging the diameter of saidvalve block. Said passage M opens through the cylindric surface of thecap I by means of a port M located near the rear end of said cap. Saidpart is in the form of a. transverse slot in the outer eylindric surfaceof the cap (see Figs. 2, 15 and 18) and is covered by the valve rine' Jwhen the same is at the rearward limit of its movement, but is leftuncovered and open to the exhaust space X when said valve ring is at itsforward limit of movement. From the foregoing description it will beapparent that when the valve ring J is at the rear limit of itsmovement, the exhaust space X is connected with the inner or rear end ofthe barrel. while. when said valve ring is at the forward limit of itsmovement, said exhaust space is connected with the outer or for ard endof the barrel.

In the rear end of the valve block cap I is formed a central annularrecess or chamber l which opens directly into the transversethrottle-valve passage G in the head. A series of annularly arrangedports 1* are provided in the cap I, said ports extending from thechamber 1 through the outer surface of said cap and being inclinedrearwardly with respect to the longitudinal central axis of the cap soas to open into an annular groove 1. located immediately forward of theshoulder l in the annular surface of the valve block, and formed partlyin the valve block body and partly in the valve block cap. Said groove Topens into the space between the shoulder J, the smaller pressure areaof the valve ring J, and the shoulder I of the valve block, which space,as ab. ve described. is always in communication with the channel J ofthe valve ring. The space between the shoulder J and the shoulder l andthe channel J are thus always supplied with live air when the throttlevalve is open.

In the valve block body H are provided a series of annularly arrangedports R, which extend. from the chamber 71 in the forward end thereof toan annular slot R in the outer surface of said valve block body near itsrear end. Said ports are inclined rearwardly and outwardly andconstitute the main supply ports for admitting live air to the inner orrear end of the cylinder. The slot 11 is adapted to be uncovered andbrought into communication with the an nular groove or channel J of thevalve ring J for the admission of air to the inner end of the cylinderwhen the valve ring J is in its forward position. (See l Thelongitudinal exhaust passage M which leads from the forward end of thebarrel, opens by means of slot or port P through the outer cylindricsurface of the valve block cap I at a point spaced longitudinally to therear of the exhaust port A The port or slot P opens into the live airspace formed by the groove or channel J when the valve ring J is in itsrearward position and is closed by said valve ring when the same is inits outer or forward position. The port or slot P. and the longitudinalpassages 1f connected therewith. constitute the supply port foradmitting air to the outer or forward one of the cylinder to drive thepiston rearward on its return stroke.

N indicates a longitudinal supply passage (see Figs. 8, 6, 16, 17 and18) formed in the wall of the cylinder A and extending through the valveblock body H and into the cap I where it opens at its rear end into thelive air chamber 1 in said cap. gaid passage N opens at its forward endinto the cylinder A through a port N located intermediate the ends ofsaid cylinder.

Q indicates a longitudinal supply passage formed in the wall of thecylinder A and extendinginto the valve block body and opening by a portQ into the space between the annular shoulder formed by the flange H fthe valve block and the annular shoulder J that is to say, the largerpressure area of the valve ring. The passage Q, opens by a port into thecylinder at a point intermediate its ends. Said port is spacedcircumferentially from but-in a transverse plane with the port N Thepiston B, near its rear end, is provided with an annular groove B (seeFigs. 1 to l, inclusive) in its outer, cylindric sur face forming anannular space about said piston by means of which the ports and N areadapted to be connected when the piston is at or near its outer limit ofmove ment. This connection directs the live air, always present in thepassage 1? on account of its connection with the live air chamber I inthe valve block cap; into the supply passage Q whence it passes throughthe port to the larger pressure area of the valve ring J and shifts saidvalve ring to its rearward position against the constant live airpressure on its smaller pressure area.

The passage Q is extended forwardly be yond the port Q to pointinteruitizdiate said port and the forward end of the cylinder where itopens into said cylinder through a second port which is closed by thepiston when the port Of is uncovered by the groove 13 to admit live airto shift the valve ring rearwardly, and which uncovered by the forwardnd of the piston on its return stroke. Auxiliary, longitudinal exhaustpassages T, T are formed in the wall of the cylinder, said passagesopening at their ends by ports T T (see Figs. 1 through said wall nearthe rear end of said cylinder into the exhaust space and opening attheir forward ends by ports T T into the cylinder at points located in atransverse plane with the port and adapted to be uncovered by theforward end of the piston on its return stroke at the same time that ituncovers the port (see Figs. 1 and 3). By this construction the passageQ. leading to the larger pressure area J of the valve ring is connectedto the exhaust space X after the forward end of the piston has passedthe ports T on the return stroke, through the port Q3, the cylinder. theports T the passages T and the ports T This relieves the live airpressure on the larger pressure area of the valve ring, so that it maybe shifted to its forward position by the constant live air pressure onits smaller pressure area.

The operation of the valve mechanism is as followsz starting with theparts in the position indicated in Fig. 4, with the plunger at the inneror rear end of its stroke, and the valve ring J at the outer or forwardlimit of its movement, the main supply ports R for admitting live air tothe rear end of the cylinder are open into the channel or groove J ofthe valve ring and the exhaust port M through which the exhaust from theforward end of the cylinder passes to the exhaust space X are also open.The supply port 1 for supplying live air to the forward or outer end ofthe cylinder, and the exh aust port K for the exhaust of the air fromthe inner or rear end of the cylinder are at this time closed. Theopening of the throttle valve G admits live air to the live air chamber1 in the valve block cap I whence it passes through the radial ports 1*in said cap to the channel. or groove J of the valve ring and thencethrough the ports R to the inner end of the cylinder. A large supply ofair is thus admitted to drive the piston with force forwardly on itsworking or power stroke, and the air at the forward end of the cylinderin advance of the piston is exhausted through the ports m, the passage Mand the exhaust port M its the piston nears the end of its for 'ardstroke and reaches the position indicated in Fig. 2, its forward endcovers the port Q and the annular groove B in the outer eylindricsurface of the piston comes in the transverse plane of the ports Q and Nthereby con necting the live air passage N which leads from the live airchamber 1 in the valve block cap, with the supply passage (3;, and thuspermitting the live air to pass through the passage it} and port Q) tothe larger pressure area J of the valve ring. This effects a movement ofthe valve ring J to the rearward. limit of its movement against theconstant live air pressure on its smaller pressure area J which itreceives through the ports ll" from the live air chamber 1. Thisrearward movement of the valve ring uncovers the exhaust ports K for therear end of the cylinder, opens the supply ports 1?, adapted to admitlive air to the forward end of the cylinder into communication with thechannel or groove J of the valve ring which contains live air and closesthe exhaust ports M and the main supply ports R, adapted, respectively,for the exhaust from the forward end of the cylinder and for the sup plyof live air to the rear end of the cylinder. In the meantime the pistonhas reached the outer or forward limit of its movement and under thepressure of live air passes through the port P and the associatedpassage and port M, m and is driven on its return or rearward stroke. Vihen, on its return stroke, the piston reaches the position indicated inFig. 1, the ports Q of the passage Q; leading to the larger pressurearea J of the valve ring and the ports T T of the auxiliary exhaustpassages T, T are simultaneously uncovered by the forward end of thepiston, thus opening the larger pressure area J of the valve ring to theexhaust space K, through the ports Q, the passage Q, the ports Q, thecylinder, the port T and the auxiliary exhaust passages and ports T, T.This relieves the pressure on the larger pressure area of the valve ringwhich is then shifted to its forward position by the constant live airpressure on its smaller pressure area J This puts the parts in the firstposition described with the exhaust ports K for the inner or rear end ofthe cylinder and the supply port P for the forward end of the cylinderclosed and the supply ports R for the inner or rear end of the cylinder,and the exhaust port M for the outer or forward end of the cylinderopen. The operation then continues as before.

It will be noted that, by reason of the arrangement of the ports R and 1and their outward inclination toward the grooves R and 1 into which theyrespectively open and which are adapted to be connected by the channel Jin the valve ring when the valve is in its forward position to connectthe inner end of the barrel to the live air supply, the valve block ismuch shortened and at the same time it is possible to provide largeports so as to produce a large admission of air into the rear end. ofthe cylinder to drive the plunger on its working stroke. A powerful toolis thus produced. In addition, by bending those passageways which extendlongitudinally through the valve block inwardly intermediate their ends,the diameter of said valve block may be reduced without affecting thecross-sectional area of said passages.

I claim as my invention 1. The combination with. a cylinder and areciprocating plunger therein, of a controlling valve for controllingthe admission and exhaust of air into and from the cylinder embracing avalve block member and a valve ring member, said valve ring memberhaving oppositely facing differential pressure areas and being adaptedto move endwise on said valve block, said valve block member havingshoulders of different areas opposing the pressure areas of said valvering and having a recess formed in each end, a circumferentiallyextending channel in saic valve ring located at the rear of the smallerpressure area thereof, a plurality of annula "ly arranged supply portsin said valve block, said supply ports being inclined said valve block,said valve block com prising a body having a central bore and a caphaving a stem fitting within said bore, and said valve block memberhaving shoulders of differential areas opposing the pressure areas ofsaid ring and having a centrally located. annular recess formed in eachend, a plurality of exhaust ports and a plurality of admission ports forthe rear end of the cylinder, said exhaust ports extending through theannular wall of the recess in the forward end of the valve block, andsaid admission ports opening through the end wall of said recess, aplurality of supply ports leading from said recess at the rear end ofsaid valve block and opening through the annular surface of the valveblock adjacent its shoulder of smaller area, and a circumferentiallyextending channel in said valve ring located at the rear of the smallerpressure area thereof, said channel being in communication with saidvalve ring in all positions thereof and being constructed. to connectsaid supply and admission ports when said valve ring is in its forwardposition.

6. The combination with a cylinder and a reciprocating plunger therein,of a controlling valve for controlling the admission and exhaust of airinto and from the cylinder embracing a valve block provided with anannular recess at its forward rear end and a valve ring having closelyapproached, oppositely facing differential pressure areas, said valveblock being provided with a plurality of radial exhaust ports throughthe annular wall of said recess, and a plurality of annularly arrangedadmission ports opening at their inner ends through the end wall of saidrecess and at their outer ends through the outer surface of said valveblock, said valve ring having a channel at the rear of its smallerpressure area adapted to communicate with the outer ends of saidadmission ports in the forward position of said valve ring, meansproviding a constant supply of live air to said channel, an exhaustpassage extending through said valve block, said exhaust passage beinginclined inwardly intermediate its ends, and an admission and exhaustport in said valve block communicating with said exhaust passage, saidlast named admission port communicating with said valve ring channelwhen the valve ring is in its rearward position.

In testimony, that I claim the foregoing as my invention I aiiiX mysignature in the presence of two witnesses, this 5th day of December A.D. 1910.

REINHOLD A. NORLING.

Witnesses Ivan A. HANssEN, Lnsrrra J. YOUNG.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G.

